1. Field of the Invention
The present invention relates to numerical controllers, and more particularly relates to a numerical controller capable of automatically classifying programs used at high frequency.
2. Description of the Related Art
To facilitate reuse of executed programs, there has been a function of recording a plurality of programs as history (see, for example, Japanese Patent Application Laid-Open No. 2013-041392). While such a function is utilized in general machining programs, the function is also often utilized in programs (hereinafter referred to as MDI programs), which are ad hoc for use in manual data input (MDI) operation executed for such minor actions as set-up of machine tools and tool replacement.
FIG. 8 illustrates an example of recording MDI program execution history.
As illustrated in FIG. 8, most of the MDI programs are adapted to perform frequently utilized simple control (in the case of FIG. 8, correction or other actions is canceled, and returning to reference point is executed). In many cases, MDI programs, which are input to perform MDI operation for the same purpose, have similar contents. Accordingly, if frequently-used MDI programs are registered in a memory of the numerical controller or other storage and be reused later, enhanced working efficiency can be expected.
In the case where programs are recorded as history and reused by using the above-stated function, workloads of a user, who searches for a target program from among a plurality of recorded programs, for reuse of the target program disadvantageously increases as the number of the programs recorded as a history becomes larger.
FIG. 9 illustrates an example in which the user conducts a work of searching for a target program in the state where an execution history of a plurality of programs is recorded. The user needs to display a list of the programs recorded as an execution history and to browse the contents of the programs in order from the top of the list to search for the target program. In the case of the example illustrated in FIG. 9, a 4th program is the target program, and the user can find the target program by browsing four programs. However, when more programs are recorded as a history, the number of the programs to be browsed may become huge, which leads to a problem of adversely decreased working efficiency.
A technology of changing the storage location of a program in accordance with usage frequency from a viewpoint of utilization efficiency of the program is disclosed in Japanese Patent Application Laid-Open No. 04-191934 and other documents. However, even if such a technology should be applied to management of the machining program history, it cannot be said that the technology is sufficient enough to enhance user's program search efficiency when the volume of recorded program history increases.